It is well known that stress and environmental aggressors such as UV light, pollution, and cigarette smoke can be very detrimental to skin and accelerate the appearance of aging. Exposure to stress and environmental aggressors often causes damage to cellular DNA, mitochondria, and cellular proteins, lipids, and tissue. Damaged cellular material found within the cell, for example, cytoplasmic or organelle debris can exert a toxic effect on cells by impeding their normal metabolic processes.
Healthy cells have a normal cleansing process that eliminates damaged cellular material and debris. Such detoxification often occurs through a phagocytic process referred to as autophagy, where the cellular debris is engulfed within a vacuole and degraded with cellular enzymes such as lysozymes. Autophagy and the mechanism of autophagy activation in skin cells is described in U.S. Patent Publication No. 2011/0243983 A1, hereby incorporated by reference in its entirety. There is much interest in formulating skin treatment compositions to contain ingredients that stimulate cellular autophagy because the ability of cells to cleanse and detoxify themselves of debris that otherwise impedes healthy metabolic function is improved. The cleansing through autophagy creates new sources of energy for cellular functions because the degradation products release building blocks such as amino acids that can be recycled by the cell. Improved cellular metabolic function in turn means improved cellular health and longevity and greater resistance to undesirable side effects of aging such as lines, wrinkles, mottled skin, hyperpigmentation, laxity and so on.
Proteasomes are large protein complexes that are found in the cytoplasm of cells. The main function of proteasomes is to degrade damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that facilitate the degradation are called proteases. Proteasomes enable cellular regulation of protein concentration as well as degradation of misfolded proteins. Such degradation yields short peptides which in turn can be further degraded into amino acids that can be recycled in the cell and used for the synthesis of new proteins. When cells become damaged, either by UV exposure or environmental assaults, the proteasomes lose effectiveness. This in turn means that cells are not detoxified of damaged cellular proteins in timely fashion. Such contaminated cells exhibit reduced metabolic function which in turn exacerbates conditions associated with aging skin such as lines, wrinkles, uneven pigmentation, laxity and so forth.
Thus, any ingredients that beneficially affect the normal cellular cleansing processes promote cellular health and longevity and minimizes the deleterious effects of environment, UV light, pollution, and other environmental insults on skin.
Accordingly it is of interest to maximize the cellular health and longevity of cells, particularly skin cells such as keratinocytes or fibroblasts, by treating them with ingredients that stimulate natural cellular repair processes by, for example, eliminating cellular debris and toxins, and in addition, to maximize the effectiveness of such cellular detoxification by ensuring that the maximum number of detoxification mechanisms are operable. It is also of interest to stimulate detoxification processes where the breakdown of the cellular debris and toxins results in amino acids or other biological molecules that can be recycled by the cell.
Thus, there is a need to maximize cellular health and longevity by stimulating selective catabolysis in cells so that cellular debris and toxins are removed and by products of such degradation may be recycled. More preferably, the selective catabolysis is due to enhancing proteasome activity, enhancing autophagy activity, and/or enhancing other cellular cleansing and/or detoxification processes.
It has been discovered that compositions containing at least one autophagy activator and at least one proteasome activator exhibit maximum effectiveness in selective cellular catabolysis, that is, cleansing cells of toxic waste products by breaking down the waste products into molecules that may be recycled and used by the cell in normal metabolic functions.